Install Sink — Apply Sealant and Mount the Sink
Part of project
How to Install an Undermount Kitchen Sink · Step 5 of 10
In this video
Carefully flip the sink over and lower it into the countertop opening, aligning it properly. Press down firmly to create a good seal with the silicone. Wipe away any excess sealant that squeezes out from the edges with a clean cloth. From underneath the cabinet, rotate the mounting clips so the hooks grab the underside of the countertop. Use a Phillips head screwdriver to tighten the screws on the mounting clips, securing the sink firmly in place. Tighten the clips in an alternating pattern (front, back, then sides) to ensure even pressure.
Goal: Set and Secure Sink
- Tighten the mounting clips until snug but do not overtighten, which could damage the sink or countertop.
- Clean up any excess sealant immediately before it starts to cure for a cleaner finish.
Used in this video
- Phillips Head Screwdriver — Tightening the mounting clips to secure the sink.
- Cloth/Rag — Wiping away excess silicone sealant.
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FAQs
Is installing an undermount kitchen sink truly an intermediate DIY project for a novice, given the 8-hour estimate?
While listed as 'intermediate' with an 8-hour estimate, the project involves critical plumbing connections, working in tight spaces, and precise sealant application, which can be challenging for beginners. If you're not confident with plumbing or power tools like a drill, consider hiring a professional for specific steps or the entire installation to avoid potential issues like leaks.
What are the most crucial specialized tools I'll need for this undermount sink installation, beyond basic household items?
Key specialized tools include adjustable and tongue and groove pliers (like the Channellock 430) for securing plumbing connections, and a reliable drill for installing the mounting clip anchors. A putty knife is essential for working with plumber's putty, and a good flashlight (like the NITECORE P20iX) will be invaluable for inspecting connections in dimly lit cabinet spaces.
What are the most common reasons for leaks after an undermount sink installation, and how can I prevent them?
Leaks typically occur due to insufficient sealant around the sink's rim, improperly tightened drain or water supply connections, or issues with the garbage disposal seal. Ensure a continuous, even bead of sealant when mounting the sink, hand-tighten plumbing connections first then give a quarter to half-turn with a wrench, and double-check all gaskets during assembly.
The project mentions Oatey Plumber's Putty; can I use 100% silicone sealant instead for mounting the sink to the countertop?
Yes, 100% silicone sealant is often preferred for undermount sinks, especially with stone countertops, as it creates a stronger, more permanent, and flexible waterproof bond than plumber's putty. While plumber's putty is excellent for sealing drains and strainers like the KRAUS Kitchen Sink Strainer, silicone offers enhanced long-term durability for the sink-to-countertop seal.
Install Sink — Apply Sealant and Mount the Sink
Part of project
How to Install an Undermount Kitchen Sink · Step 5 of 10
In this video
Carefully flip the sink over and lower it into the countertop opening, aligning it properly. Press down firmly to create a good seal with the silicone. Wipe away any excess sealant that squeezes out from the edges with a clean cloth. From underneath the cabinet, rotate the mounting clips so the hooks grab the underside of the countertop. Use a Phillips head screwdriver to tighten the screws on the mounting clips, securing the sink firmly in place. Tighten the clips in an alternating pattern (front, back, then sides) to ensure even pressure.
Goal: Set and Secure Sink
- Tighten the mounting clips until snug but do not overtighten, which could damage the sink or countertop.
- Clean up any excess sealant immediately before it starts to cure for a cleaner finish.
Used in this video
- Phillips Head Screwdriver — Tightening the mounting clips to secure the sink.
- Cloth/Rag — Wiping away excess silicone sealant.
Frequently Asked Questions
Is installing an undermount kitchen sink truly an intermediate DIY project for a novice, given the 8-hour estimate?
While listed as 'intermediate' with an 8-hour estimate, the project involves critical plumbing connections, working in tight spaces, and precise sealant application, which can be challenging for beginners. If you're not confident with plumbing or power tools like a drill, consider hiring a professional for specific steps or the entire installation to avoid potential issues like leaks.
What are the most crucial specialized tools I'll need for this undermount sink installation, beyond basic household items?
Key specialized tools include adjustable and tongue and groove pliers (like the Channellock 430) for securing plumbing connections, and a reliable drill for installing the mounting clip anchors. A putty knife is essential for working with plumber's putty, and a good flashlight (like the NITECORE P20iX) will be invaluable for inspecting connections in dimly lit cabinet spaces.
What are the most common reasons for leaks after an undermount sink installation, and how can I prevent them?
Leaks typically occur due to insufficient sealant around the sink's rim, improperly tightened drain or water supply connections, or issues with the garbage disposal seal. Ensure a continuous, even bead of sealant when mounting the sink, hand-tighten plumbing connections first then give a quarter to half-turn with a wrench, and double-check all gaskets during assembly.
The project mentions Oatey Plumber's Putty; can I use 100% silicone sealant instead for mounting the sink to the countertop?
Yes, 100% silicone sealant is often preferred for undermount sinks, especially with stone countertops, as it creates a stronger, more permanent, and flexible waterproof bond than plumber's putty. While plumber's putty is excellent for sealing drains and strainers like the KRAUS Kitchen Sink Strainer, silicone offers enhanced long-term durability for the sink-to-countertop seal.